That changed with 7th edition that came out this past year. The new APA guideline is one space after end punctuation unless requested otherwise by an instructor. This would not be an issue if I managed to get my doctoral study completed and approved this year as I would grandfathered into 6th edition APA, but as it looks like everything will not be finished until next year, I will probably need to make the change to 7th ... and only one space.
For this reason, starting with this blog post, I am trying to break a multi-decade habit and only place one space after my end punctuation (and colons). It has not been easy. For the most part, I'm still hitting the spacebar twice and then immediately hitting the backspace. At least, that's been the case for all of the sentences in this post except one.
This just feels wrong.